A torsional vibration damper of the type mentioned above can be seen from US20140090514 in FIG. 3. This torsional vibration damper is provided for a hydrodynamic coupling arrangement having a hydrodynamic circuit formed by an impeller, a turbine and a stator. The input of the torsional vibration damper is operatively connected to a drive such as an internal combustion engine via a clutch device serving to bypass the hydrodynamic circuit during predetermined operating states, while the output of the torsional vibration damper is operatively connected to a driven side which is implemented, for example, as a torsion damper hub. Accordingly, the output of the torsional vibration damper is connected not only to a torsion damper hub but also to a mass damper system and to the turbine, and the turbine acts as a mass arrangement associated with the output of the torsional vibration damper.
In torsional vibration dampers having a damping device whose output is connected to a mass damper system as well as to a mass arrangement, there is the advantage of minimal rotational irregularity even under full load at very low speeds, for example, at a speed of 1,000 revolutions per minute. In conflict with this advantage, however, is the fact that there is a significant rise in rotational irregularity at higher speeds, for example, within a speed range of 1,500 to 1,800 revolutions per minute. This rise in rotational irregularity is accompanied by sharply declining deflection angles at the output of the damping device even when torsional vibrations are present at the input of the damping device. This behavior of the damping device, the output of which stays at least approximately in a vibration node, is determined through effects from the transmission arrangement. It is particularly disadvantageous for the output of the damping device to persist in a vibration node because this would dispense with the vibration excitations which are vital for the functioning of damper masses of the mass damper system connected to the output of the damping device. This is especially true with respect to the above-mentioned significant increase in rotational irregularity.
It is an object of the invention to construct a torsional vibration damper with a damping device, whose output is connected to a mass damper system and also to a mass arrangement, such that an increase in rotational irregularity in a determined speed range is at least limited.